The present invention relates to oil cooler bypass valves, and more particularly to a bypass valve which is couplable to an oil source which is thermally responsive to changes in oil temperatures.
Oil cooler bypass valves are used in conjunction with engines, transmissions, power steering systems, and hydraulic systems. They are designed to provide a flow path by which oil passing to the valve from the oil source is returned without passing through a heat exchanger during warm-up periods.
Typical transmission bypass valves have several connecting joints and complicated return features which increases costs and the likelihood of failures caused by leaks. In most prior art systems, the valve member is an integral part of a thermally responsive element which expands to cause the valve member to engage the valve seat. Once seated such a valve member is susceptible to at least two malfunctions. It is impossible to unseat the valve member to relieve excessive system pressures which may occur if the valve ports are improperly connected to the cooler or in the event the oil line is damaged or blocked or the cooler itself has become inoperable. Secondly, the components of the bypass valve are often damaged when the thermally responsive element continues to expand, which sometimes occurs when the cooler is overloaded and the oil heats excessively. Such damage can include cracking of the valve member mounting, or internal failure of the valve components. In either case the bypass valve is unfit for further service.
According to the present invention, an oil/fluid cooler bypass valve is provided for use in conjunction with a cooling system of the type which includes a manifold type valve housing having a valve chamber communicating with an oil/fluid supply, fluid return, cooler supply, and cooler return lines. A valve member having a cooling position for directing fluid from the fluid supply line to the cooler supply line for circulation through a cooler, and then from the cooler return line to the oil return line. The valve has a warm-up position for directing oil from the oil supply line back to the oil return line, thus bypassing the heat exchanger.
The valve actuation mechanism of the present invention is operative to move the valve member between its warm-up and cooling positions and comprises an element responsive to changes in temperature or pressure of the fluid prior to entry to the cooler. The responsive element is integral with the valve member. The valve member is enclosed with a manifold which is fastened directly to the oil containing body. In one embodiment of the invention, the manifold is directly seated against the oil containing body.
In another embodiment of the present invention, the valve body has a pair of integral input and output ports. Machined into the cavity about the ports are a pair of notches configured to accept O-ring seals. These O-ring seals function to seal the ports when they are bolted directly onto the oil containing body.
In another embodiment of the present invention, an insertable valve element is disclosed. The valve element has a component which is responsive to changes in temperatures. The thermal component has a first valve bearing surface which mates upon a first valve seat within the valve body and a second bearing element which seals a second valve seat. Disposed between the first valve seat and an annular flange on the thermal element is a first spring which functions to bias the first bearing surface against the first valve seat at temperatures above a pre-determined level. A second bi-pass spring is disposed between the thermal element and the mounting member. The mounting member is used to fixably couple the valve element within the valve body.
In yet another embodiment of the present invention, the valve element having a sliding valve component is disclosed. The sliding valve component has an axial through bore which mates to an outer surface of a thermal element. The sliding valve member further has a through passage which regulates the flow of oil through the valve.